The electrochemical determination of l-cysteine at a Ce-doped Mg–Al layered double hydroxide modified glassy carbon electrode

A Ce-doped Mg–Al layered double hydroxide modified glassy carbon electrode (Mg–Al–Ce LDH/GCE) was fabricated for the detection of l-cysteine (CySH). The electrochemical behavior of CySH on the as-prepared electrode was investigated by cyclic voltammetry. Our results show that Mg–Al–Ce LDHs gave an enhanced oxidation wave of CySH at the modified electrode. The effect of pH value and scan rate on CySH oxidation was studied in detail, and the mechanism of CySH oxidation on the Mg–Al–Ce LDH/GCE was also addressed. The amperometric current of the electrode is proportional to the concentration of CySH over the range of 10–5400 μM, with a detection limit of 4.2 μM at a signal-to-noise ratio of 3. The low cost, fast amperometric response, wide linear range, excellent stability, good selectivity and easy preparation are some of the notable advantages of this electrode.

► Ce-doped Mg–Al LDHs were synthesized by a coprecipitation method. ► A modified electrode based on the LDHs for sensing of l-cysteine was fabricated. ► The proposed sensor features a wider linear range and better selectivity.